Diffuse White Spots of the Duodenum May Suggest Glucose Malabsorption

Abstract

Purpose: It has been unclear what endoscopic finding reflects small intestinal malabsorption. At panendoscopy, the second part of the duodenum was usually observed, and diffuse white spots were found in some patients. This endoscopic finding is considered to reflect abnormal lipid transport from the villi of the small intestine. The aim of this study is to evaluate the relationship between white spots observed in the duodenum and malabsorption of nutrient. Methods: Consecutive 165 subjects who underwent upper gastrointestional endoscopy were recruited in this study. At endoscopy, a tip of endoscope was placed to the second part of the duodenum and 20 ml of water containing 100 mg of 13C-glycine (N = 65), 13C-acetate (N = 65), and 13C-glucose (N = 35) was infused into the duodenum. Breath samples were taken at baseline and at 10-min interval for 30 min, 60 min, and 90 min after administration in 13C-acetate, 13C-glycine, and 13C-glucose breath test, respectively. The 13C/12C ratio of each sample was analysed and were expressed as delta over baseline. Absorptive function was determined as cumulative% dose at the endpoint of sampling. Results: Patients were divided into three groups according to the grade of duodenal white spot as follows; “absent,”“patchy,” and “diffuse.” The mean values of cumulative% dose at 30 min of acetate were 7.3 ± 2.5%, 6.8 ± 2.8%, and 7.1 ± 1.3% in the “absent,”“patchy,” and “diffuse” group, respectively. For absorptive function of glycine, the mean values of cumulative% dose at 60 min were 11.4 ± 4.0%, 11.7 ± 4.0%, and 12.8 ± 3.0%, respectively. For glucose, these values at 90 min were 7.1 ± 1.3%, 5.9 ± 2.2%, 5.7 ± 1.5%, respectively. Conclusions: Differences in absorptive function of acetate and glycine were not found between patients with and without duodenal white spots, whereas absorptive function of glucose tended to be lower in patients with duodenal white spots. White spots observed in the duodenum may be one of endoscopic findings, reflecting malabsorption of glucose.